Método para priorização de ações de vigilância da presença de agrotóxicos em águas superficiais: um estudo em Minas Gerais

Abstract

The pesticide occurrence in water for human consumption is a growing concern in Brazil that needs to be evaluated better and foreseen, due to the possible adverse effects to the environment and the human health. The applied pesticides in the agriculture, important source of contamination, can persist in the agriculture product or for several years in the soil, be dispersed by the wind or reach superficial and ground waters. The evaluate of them in springs is still precarious, being also preoccupying your low removal in water treatment system. The research intended to develop a method to priories surveillance actions of the pesticide presence in surface water and to apply it in sub-basins of Minas Gerais. The detection of critical points was based on the physical and chemical proprieties of the pesticides, your environmental and toxicological classifications, environmental characteristics of the studyarea and of agricultural activity, contemplating the striped pesticides in the Portaria MS 518/2004 and in the WHO Guidelines. The pesticides were divided in six groups (high, medium and low potential contamination of superficial sources, associated to the sediment or dissolved in water), for the method of Goss. Important agricultural cultures were selected in terms of productivity, agricultural area andproduction, leaving for identification of areas and, soon after, of the main sub-basins for the selected area. A variety of possible pesticides is observed to be applied for agricultural culture. The sub-basins with high potential of contamination for pesticide were selected and organized through the multicriteria analysis, using the TOPSIS method. Five criteria were formulated and the weights for each one were defined. The application of the method in Minas Gerais resulted in the selection of five sub-basins of the Grande River Basin, south area of the State, that is characterized by the production of coffee, potato and corn. The multicriteria analysis pointed the sub-basin GD3 (around Furnas Reservoir) as priority, and it showed coherence for appearing, as main areas for monitoring, those with high percent of productivity and of producing municipal districts, especially of coffee, potato, bean andcorn. The study in Minas Gerais allowed to validate and to adjust the proposed method and to reinforce the relationship among the agricultural culture and the potential of contamination that the pesticides can exercise on the surface water.